Electric switch



G. A. BURNHAM.

ELECTRIC SWITCH.

APPLICATION FILED MAY12,1919.

1,409,997. Patented Mar. 21,- 1922.

3 SHEETS-SHEET l.

G. A. BURNHAM.

ELECTRIC SWlTCH.

APPLICATION FILED MAY 12, 1939. 1,409,997. Patented Mar- 21, 1922.

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G. A. BURNHAM.

ELECTRIC SWITCH.

APPLICATION FILED MAY 12, 1919.

Patented Mar. 21, 1922.

3 SHEETS-SHEET 3.

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UNITED STATES PATENT OFFICE.

GEORGE A. BURNIIAM, OF SAUGUS, MASSACHUSETTS, ASSIGNOR TO SEARS B. GONDI'I, 312., OF BRQOKLINE, MASSACHUSETTS.

ELECTRIC SWITCH.

Application filed May 12,

To all whom it may concern Be it lrnown that'l, Gnonen ii. Bmmrmir, a citizen of the Unitec States, a resident of Saugus, in the county of Essex and State of .li'lassachusctts, have invented an Improve ment in Electric Switches, of which the following is a specification.

This invention relates to electric oil switches and has for its object to provide means for increasing the current-carrying capacity of the switch by combining therewith an improved form of cooling means, and is intended as an improvement upon the device of my Patent No. 1,337,995, dated April 27,1920.

Another object of this invention is to provide an electric switch with self-contained cooling means, which shall be simple and cheap in construction, and effective in operation.

A further object is to provide an electric switch with self-contained cooling means adapted for automatic operation by the cur rent passing through the switch.

A further object is to provide a self-contained cooling means, made as an attachment and adapted to be applied to an electric switch by which the capacity of an existing switch may be increased.

The cooling means consists of an oil receptacle for the electric switch having heat radiators by which the radiating or heat dissipating surfaces are increased. The heat radiators may comprise oil conductors having heat radiating surfaces carried by the oil receptacle and in communication with the oil contained therein. Hot oil is adapted to flow from the receptacle into the radiators to be cooled and from the radiators in cold condition to the receptacle to abstract heat from the heated components of the switch. The oil receptacle and radiators are ada ted to form a unit which may replace the oil receptacle of an existing switch and increase its capacity by reducing the temperature rise of the switch.

A further object of the invention is the provision of means for the collection of carbon which is separated from the oil in which the switch members are immersed and also for the collection and separation of moisture from the oil; and this object is attained by means of a settling chamber formed as a component of the oil circulatory system and Specification of Letters Patent.

Patented Mar. 21, 1922.

1913'. Serial No. 296,397.

in which the solid particles and moisture collect and are retained.

Fig. l is a partial side view of a multiphase switching apparatus embodying my invention.

Fig. 2 is a vertical central section through a switch of Fig. 1.

Fig. 3 is a section along lines of Fig. 2.

Fig. is a sectional detail of a modified form of my invention.

Fig. 5 is a side view of an oil receptacle and radiators formed as a unit and detached from the switch.

Fig. 6 is a sectional view of an oil receptacle and radiator with the settling chamber incorporated with the receptacle.

Fig. 7 is a partial sectional View of an oil receptacle and radiator with the settling chamber incorporated with the radiator.

Fig. 8 is a front view of Fig. 7.

I have chosen the switch set forth in my copending application filed June 17, 1918, Serial No. 2%,317, for the purpose of illustrating my invention although it may be applied to other oil immersed switches.

is here shown, the switching apparatus comprises the back-bone 10 from which the independent switches of the apparatus are suspended. Each switch comprises the switch frame 11, the stationary switch members l2 and movable switch members 13 depending from frame. The oil receptacle is, adapted to contain oil in which said switch members are immersed, is of usual box structure having walls of sheet iron or steel, and is removably secured to the switch frame by means of the bolts 16 and wing-nuts 17, the removal of which permits the receptacle to be lowered from the switch frame for its removal.

1 lining 18 of insulating material is arranged within the oil receptacle and as here shown is in actual contact with the walls thereof although in commercial manufacture it may be spaced a small distance therefrom, as a manufacturing expedient. Said linings, usually, and as shown, ext-end above the level of oil in the receptacle, although switches and oil receptacles are constructed with linings which terminate beneath the oil level, the particular a rangement being a matter of judgment on the part of the designer.

The heat radiators associated with the oil receptacle and as shown in Figs. 1 to 5 inclusive comprise the plurality of fluid conductors or pipes 20. Said pipes are formed, preferably, of material having high heat conductivity with surfaces of high heat dissipating ability and the dissipating ability may be enhanced by providing additional radiating surface, as by the discs 21, Fig. l, which are spaced apart on the fluid conductors to insure unrestricted circulation of air therebetween, and are in good heat conducting union with said conductor.

Openings 25 are :tormed through the walls of the oil receptacle near the bottom hereof, and registering openings 26 are formed through the lining. Similar openings 27 and 28 are formed respectively in the receptacle and lining near the top thereof and below the level of oil in the receptacle for the purpose of providing fiuid communication b tween the heat radiators or conductors 20 and the body of oil within the receptacle.

Said conductors are formed of single lengths of tubing reflexed at the end-portions, as at 20 and 20 and they are arranged substantially vertically and said end-portions are secured in fluid tight union with the walls of the receptacle, in register with the openings therein by welding, or other suitable means, whereby the hot oil. may enter the radiators at the top through openings 27 and 28 and flow down the conductors, being cooled in its passage therethrough and enter the oil receptacle through the openings 25 and 26 in the oil receptacle and lining tocirculate upward within the oil receptacle and abstract heat from the heated COlTlponents of the switch.

I prefer to arrange my heat radiators on the ends of the oil receptacle whereby the switches may be spaced closely together and thereby occupy less space than could oth rwise be the case. Such an arrangement i also preferable when the oil receptacle with heat radiators is to replace the oil receptacle of a switch having no provision tor its cooling as the exchange of receptacles may be accomplished without in any ray altering the spacing of the switch unit in a multiphase switching arrangement. Furthermore, a more eiiicient heat-dissipating arrangement obtains inasmuch as there is an unimpeded circulation of air about the surfaces of the radiator and there is no int-en ference between radiators of adjacent switches of a switching apparatus.

In Fig. 4 I have illustrated the cooled oil as entering the receptacle trom the radiator through the bottom thereof whereby it may be directed in a more ellicicni'; manner over the switch members to abstract heat therefrom. A rather greater heat-dissipat ing surface of the radiator may also result from this arrangement.

.L'Llthough l have here shown the heat radiators as comprising a plurality of [luid conductors having heatradiating HH'i QICLS and each indcpciulently connected with the oil receptacle yet it is ol. viou;--: that other well known forms and arrangements of radiators may be utilized, when desired.

The circulation of oil in the oil receptacle and heat radiators depends upon the difference in specific gravity ol hot and cool oil. The hot and light oil rises to the :surl'acc in the receptacle and flows into the radiators where itbecomes cooled. The cold oil has greater density than the hot oil and consequently flows downward in the radiators and enters the bottom ol the oil receptacle in cooler condition.

The oil in the oil receptacle gradually carbonizes, with repeated switch o nj-ration. and the separated carbon gradually settle and collects in the bottom of the oil receptacle. The separated and precipitated carbon does not particularly elli'cct the operation of the switch in interrupting a circuit in that type oi switch having no provision for the active circulation of oil for its cooling, when the period between consecutive operations of the switch is snilh'eiently extended to permit the settling of the carbon stirred up at each operation. In switches having provision tor the active circulation of the oil within the oil receptacle, for the forced cooling of the switch, the rate of flow 'ol the oil may be so great as to entrain the particles of carbon and prevent scttlii'ig thereof and the insulating properties may therelw hecome impaired. For this reason it is dcsirablc to provide means to collect the carbon particles to thereby prevent impairment of the insulating properties of the oil which may result From the circulation of such ca rbon particles.

This result may be accomplished by pro riding a settling chan'iber tor the carbon particles, in which the velocity ot the oil. in its circulation, is so low that the carbon particles fall by their weight and collect in the chamber. loistnre also graduallv c llects in the oil and may also be sc niratcd therefrom by settling in said chamlr-ci:

In Fig. (3 l have :l'ormcd the sc"tlin; chann her as a component part ol the oil receptacle itself. The discharge pipe 30 ot the heat radiator enters the oil receptacle :2. a suitable height above the b ttom thereof where]. a quiescent body of oil is provided. between the entrance of oil from the radiator and the bottom of the tank, as at 31. in which the separated carbon particles are precipitated and retained as a sludge. Each switch operation may stir up the sludge but it will mm collect in the bottom of the settling clluiilln. and only clear oil will then be circulated through the receptacle and heal radiators.

In Figs. 7 and S I have shown a s ttling chamber associated with the heat radiator. l

The heat radiator here shown comprises an intake manifold 40 and a discharge manifold h, each having a volume sutlicient to properly distribute the oil to the oil conductors of the radiator for its cooling. A plurality of pipes or conductors 42 are extended between said manifolds and have a combincd heat dissipating surface sutlicient to dissipate the heat generated in the switch components. The intake manifold is connected by the intake pipc l ito the receptacle which communicates therewith. beneath the surface of the oil in the oil receptacle and the discharge manifold is connected with the oil receptacle through the discharge pipe to which, in this construction, may communicate with the oil receptacle at the bottom thereof. Couplings 4-6 form a component part of said intake and discharge pipes whereby the radiator may be conveniently removed from the receptacle.

The sludge settling chamber is here formed as a component part of the discharge manifold. The side walls 4L1 thereof extend a substantial distance below the connection of the discharge pipe therewith. and the bottom wall 41" tapers toward the center of the manifold to a sludge outlet M which is closed by the removable plug t8. The chamber thus formed below the outlet from the discharge manifold forms a compartment in which the carbon particles in the oil circulated through the-radiator may settle and the oil in the receptacle may thereby remain free from carbon. lVit-h this form a second switch operation may occur innnediately after the first operation and yet the second operation is just as effective in interrupting; the circuit as the first operation.

hen the sludge has collected in a sufficient quantity it may be removed by remov ing the plug L8 from the opening 47, and the. oil also drawn off may be replaced by fresh oil introduced into the system. through the filler neck 50 in the top of the intake manifold.

I claim 1. An electric switch comprising. the combination of stationary and movable switch members, a receptacle adapted to contain oil in which said members are immersed and one or more fluid conductors arranged at the outside of said receptacle and exposed to a cooling temperature which are in open communication with said receptacle near the top and bottom thereof and below the oil level therein for the thermal circulation. of the fluid contained in the receptacle, and dissipation of the heat contents thereof.

2. his a new article of manufacture, a electric switch having a tank adapted to contain oil in which the switch components are immersed and heat radiators comprising one or more isolated fluid conductors carried by said tank arranged in open communication with said tank at the upper and lower ends thereof and below the oil level therein for establishing thermal circulation of the con tents of the tank.

3. .is a new article of manufacture, an electric switch having a tank adapted to contain oil in which the switch components are immersed and heat radiators comprising a plurality of fluid conductorsconnected with said tank at the upper and lower ends thereof and below the oil level therein and tending into a reducing temperature for the thermal circulation of the fluid by which the heat from the tank is carried away.

4. An electric switch comprising the combination of a switch frame, stationar and movable switch members carried thereby, an oil receptacle adapted to contain oil in which said members are immersed, means to removably secure said receptacle to said switch frame, oil cooling pipes carried by said receptacle on the outside thereof having an inlet near the top of the receptacle and below the oil level therein for the passage of hot oil from the receptacle to said cooling pipe. and having an outlet near the bottom of the receptacle for cooled oil from the cooling pipes to the receptacle by which to establish a. thermal circulation of, and cool, the contents of the receptacle.

5. The combination, in an electric switch, of an oil receptacle adapted to contain oil in which switch components are immersed, and heat radiators carried by the receptacle on the outside thereof having means for establishing open communication with the oil space within the receptacle.

(3. 311 electric switch comprising the combination of a switch frame, movable and stationary switch members carried thereby, an oil receptacle adapted to contain oil in which said switch members are immersed, heat radiators carried by said receptacle on the outside thereof, having means for establish ing fluid communication between said radiators and the interior of said oil receptacle, and means to removably secure said oil receptacle with associated radiators to the switch frame.

7. An attachment for electric switches comprising an oil receptacle adapted to contain oil in which switch components are immersed, heat radiators carried by said receptacle on the outside thereof. in open communication with the interior of said receptacle, and means to removably secure the attachment to an electric switch.

8. An electric switch comprising the com.- bination of stationary and movable switch members, a receptacle adapted to contain oil in which the switch members are immersed characterized by having side-walls and endwalls, and heat-radiators carried by the receptacle on the outside at its end-walls in open communication with the oil space in the receptacle.

9. in attachment for electric switches comprising a receptacle adapted to contain oil in whlch the switch members are 1mmerscd characterized by having side-walls and end-walls, and heat-radiators carried by the receptacle on the outside at its endwalls in open communication with the oil space in the receptacle.

10. An electric switch comprising movable and stationary switch members, a receptacle adapted to contain oil in which the switch members are immersed, a lining of insulating material disposed within the receptacle at the side walls thereof, a plurality of vertically disposed radiator pipes carried by the receptacle on the outside, and said side walls and lining of said receptacle having a plurality of registering openings to establish open communication between said radiator pipes and the oil space of said receptacle.

11. An electric switch comprising movable and stationary switch members, a receptacle adapted to contain oil in which. the switch members are immersed, a lining of insulating material disposed within the receptacle adjacent the walls thereof, heatradiators carried by said receptacle on the outside thereof and the side-walls and lining of said receptacle having registering openings to establish open communication between said radiators and the oil space in the receptacle.

12. An oil receptacle for electrical apparatus having a heat radiator carried on the outside thereof, an insulating lining disposed within it adjacent its side wall and registering openings in its side wall and lining to establish open communication between the radiator and the oil space of the receptacle.

13. An attachment for electric switches comprising an oil receptacle adapted to contain oil'in which switch components are immersed, a lining of insulating material disposed within said receptacle and adjacent the walls thereof, heat radiators carried by said receptacle on the outside thereof, said oil receptacle having openings through its walls and lining to establish open communication between said radiators and the interior of said receptacle, and means to secure the attachment to an electric switch.

14-. An electric switch comprising station ary and movable switch members, an oil receptacle adapted to contain oil in which said members are immersed, a cooling circulatory system for the oil including heat radiators carried by said receptacle, and a settling chamber connected with said oil circulatory system.

15. An electric switch comprising stationary and movable switch members, an oil receptacle adapted to contain oil in which said members are immersed, a cooling circulatory system for the oil including heat radiators carried by said receptacle, and a settling chamber connected with said oil circulatory system and means to removably secure said oil receptacle with associated element to the switch.

16. An attachment for electric switches comprising an oil receptacle adapted to contain oil in which switch components are immersed, an oil circulatory and cooling system associated with and carried by said rc ceptacle, a settling chamber connected with said circulatory system, and means to removably secure said attachment to an electric switch.

17. In an electric switch comprising stationary and movable switch members, and an oil. receptacle adapted to contain oil in which said members are immersed. a circulatory and cooling system for the oil in said receptacle whereby the switch is cooled, a heat radiator forming a component of said circulatory system carried by said receptacle on the outside thereof. and a settling chamber connected with said. radiator.

18. In an electric switch comprising stationary and movable switch members, and an oil receptacle adapted to contain oil in which said members are immersed, a circu latory and cooling system for the oil in said receptacle whereby the switch is cooled. a heat radiator forming a component of said circulatory system carried by said receptacle on the outside thereof, and a settling chamber included in said circulatory system external the oil receptacle to remove solid particles from the circulated oil.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

GEORGE A. BURNHAM.

Witnesses T. T. GREENWOOD, H. B. DAVIS. 

